package com.etc.exec;

public class Test {
    public static void main(String[] args) {
        Master m = new Master();
        Dog d = new Dog();
        d.setName("小黑");
        m.play(d);

        Pet t = new Dog();
        
        t.setName("小白");
        t.play(t);

        Pet t2 = new Penguin();
        t2.setName("QQ");
        t2.play(t2);
    }
}
